Sound-deadening device for phonograph reproducers



E. F. DAHLHEIM AND W. S. HULET.

I SOUND DEADENING DEVICE FOR PHOI VOGRAPH REPRODUCERS. APPLlCATlON FILED DEC. I3, 1920- 1,414,9s7. Pat nted Mafl, 1922.

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" i se r s ERN EST F. DAHLHEIIVI AN D WALTER S. HULET,

OF IEINOT, NORTH DAKOTA.

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Specification of Letters Patent.

Application filed December 13, 1920. Serial No. 430,355.

T 0 all whom it may concern Be it known that we, ERNEST F. DAHL- 11mm and lVALrnR S. HULnr, citizens of the United States, residing at Minot, in the county of Vard and State of North Dakota, have invented certain new and useful Tmprovements in Sound-Deadening Devices for Phonograph Reproducers; and we do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to new and useful improvements in sound deadening or regu lating devices for phonograph reproducers and has for its primary object the provision of a device of the above stated character which may be easily and quickly applied to an ordinary sound box and is provided with means for regulating the vibration of the vibratory transmitter bar so as to increase and decrease the sound and thereby obviate the employment of different types of styluses now used for such purpose.

Another object of this invention is the provision of a sound deadening or regulat ing device for phonograph reproducers of the above stated character, which will be simple, durable and eilicient, and which may be manufactured and sold at a comparatively low cost.

With these and other objects in view as will become more apparent as the description proceeds, the invention consists in certain novel features of construction, combination and arrangement of parts will be hereinafter more fully described and claimed.

For a complete understanding of our. invention, reference is to be had to the following description and accompanying drawings, in which:

Figure 1 is a side elevation of a sound deadening or regulating device applied to a reproducer and constructed in accordance with our invention,

Figure 2 is a rear elevation illustrating the same and removed from a reproducer,

Figure 3 is a sectional view illustrating the device applied to a reproducer.

Figure 4 is a detail sectional view illustrating means for urging the clamping members into engagement with the vibratory transmitter bar, I,

Figure 5 is a detail sectional View illustrating an adjustment for the clamping arms or members,

Figure 6' is an edge view, illustrating a modified form of our invention.

Referring in detail to the drawings, the numeral 1 indicates a reproducer consisting of a sound box 2 having the usual diaphragm 3 to which is connected the mitter bar 4; and the latter is connected to a stylus 5 by way of a stylus holder 6. The foregoing description relates to a well known construction of reproducer and to which our invention may be applied.

An attaching member 7 consisting of an annular body 8 has formed upon its outer periphery or edge an annular flange 9 adapted to engage over the sound box 2 of the re producer as illustrated in Figure 3.

The annular body 8 is provided with a cut away portion 10 so as to provide a space for receiving the'stylus member 6 and prevent the same from being interfered with by the holder 7. The flange 9 is provided with a series of set screws 11 adapted to be turned into engagement with the sound box .2 for retaining the body 8 thereon and which will permit the body to be easily removed when desired. 7

The annular body 8 is provided with a central opening 12 which is disposed over the diaphragm 8 and the vibratory transmitter bar. A pair of arms'13 extend in parallelism and have one of their ends bent angularly and extended in di erging planes and pivoted to the body 8 as illustrated at 14. The parallel portions of the arms 13 are arranged on opposite sides of the vibratory transmitter bar and have secured thereto blocks 15. The blocks 15 are provided-with recesses 16 which receive the arms 13 and said arms 13 are of a diameter less than the diameter of the recesses so as to form seats to receive pads 17. The pads 17 are adapted to engage the vibratory transmitter bar upon opposite sides and one of said pads is of a greater length than the other as illustrated in Figure 2 so as to provide a device which will be more effective in regulating the sound. The blocks 15 have formed therein recesses 18 which communicate with openings extending through said blocks and in which are mounted set bolts 19. The bolts 19 have heads 20 formed on one of their ends and said heads are located within the recesses 18 and the other ends of the bolts 19 Patented May 2, 1922. a

vibratory transhave threaded thereon adjusting nuts 21. Expansion or coil springs 22 are mounted on the bolts 19 and interposed between the inner walls of the recesses 18 and the heads 20 and nuts 21 of the bolts 19 for the purpose of urging the blocks 15 in the direction of each other and consequently causing the pads 17 to bring about pressure upon the vibratory transmitter bar thereby to reduce the vibration of said bar and thus reduce the sound from the reproducer.

An adjusting rod 23 is threaded into one of the blocks 15 and has a reduced inner end 2st received within a recess formed within the other block 15 and by adjusting said red the blocks 15 will be forced apart reducing the pressure of the pads on the vibratory transmitter bar and thereby increase the sound from the reproducer.

From the foregoing description taken in connection with the accompanying drawings it will noted that a device has been provided which may be easily and conveniently applied to a sound box when desired for the purpose of governing the sound :trom the sound box and it is, to be understood that the attaching member 7 may be of any desired shape to fit sound boxes or reproducers now on the market.

Referring to my modified form of invention as shown in Figure 6, the parallel portions or the arms 13 are inclined outwardly from the body so that the device will fit another form or" reproducer from that shown in the drawings.

While we have shown and described the preferred embodiment of our invention, it will be understood that minor changes in construction, combination, and arrangement of parts may be made without departing from the spirit and scope of the invention as claimed. 4

What is claimed is 2- 1.. A sound regulating device for phonograph reproducers comprising an attaching member detachably secured to the sound box of a reproducer, parallel arms having one of their ends angularly related and extending in diverging planes and pivoted to said attaching member, blocks secured to the parallel portions of said arms and arranged in opposite sides of the vibratory transmitter bar of the reproducer, pads carried by said blocks for engagement with the bar, tension means for urging the blocks in the direction of each other to cause the pads to bear upon the bar, and means for moving the blocks away from each other to reduce the pressure of the pads on the; bar.

sound deadening device for phonograph reproducers comprising an attaching member detachably secured to the sound box of a reproducer, parallel arms having diverging ends pivoted to the attaching member, blocks secured to the parallel portions of said arms and arranged on opposite sides of the vibratory transmitter bar of the reproducer and having recesses, pads located in said recesses and varying in length and bearing against the bar upon opposite sides, tension means urging the blocks in the direction of each other, and manual control means for moving the blocks away from each other.

3. A sound regulating device for phonograph reproducers comprising an attaching member, means detachably securing said member to the soundL box of a reproducer, arms pivoted to said attaching member, blocks carried by said arms, pads carried by said blocks and engaging the vibratory transmitter bar of the reproducer, said blocks hav ing recesses and openings communicating with each other, adjusting bolts extending through said recesses and opening-s, heads formed on one of the ends of said bolts, nuts threaded to the other ends oi said bolts, springs mounted on said bolts within said recesses and bearing against the inner walls of the recesses and the heads and the bolts for urgii'ig the blocks in the direction of each other, and. an adjusting rod threaded to one of said blocks and bearing against the other block to force said blocks away from each other.

In testimony whereof we affix our signatures in the presence of two witnesses.

Fir NEST F. Di XHLHEIM. HALTER S. l-IULET. lVitnesses "for Ernest F. Dahlheim:

C. B. DAvis, G. A. Jones. Witnesses for lValter S. Hulet:

U. Hnrmrnsniv,

J. H. Um. ,1 

